Minor bug fixes.

AssetExtractor/Program.cs

@@ -55,6 +55,8 @@ public static class Program
         string? currentList = null;
         string itemName = "";
         int tileW = 0, tileH = 0;
+        bool transparent = false;
+        string transparentColor = "clBlack";
         StringBuilder? hex = null;
         byte[]? pictureData = null;
         int itemIndex = 0;
@@ -64,7 +66,8 @@ public static class Program
             if (currentList == null || pictureData == null) return;
             string safeName = itemName.Length > 0 ? itemName : "unnamed";
             string file = $"{currentList.ToLowerInvariant()}_{itemIndex:D2}_{safeName}.png";
-            SaveGraphic(pictureData, Path.Combine(_outDir, "gfx", file));
+            SaveGraphic(pictureData, Path.Combine(_outDir, "gfx", file),
+                transparent ? ParseDelphiColor(transparentColor) : null);
             manifest.TryAdd(currentList, []);
             // TileWidth/TileHeight of 0 means "whole image is one frame"
             manifest[currentList].Add(new ImageItem(itemIndex, itemName, file, tileW, tileH));
@@ -73,6 +76,8 @@ public static class Program
             pictureData = null;
             itemName = "";
             tileW = tileH = 0;
+            transparent = false;
+            transparentColor = "clBlack";
         }
 
         foreach (var raw in lines)
@@ -116,6 +121,10 @@ public static class Program
                 tileW = int.Parse(line["TileWidth = ".Length..]);
             else if (line.StartsWith("TileHeight = "))
                 tileH = int.Parse(line["TileHeight = ".Length..]);
+            else if (line.StartsWith("TransparentColor = "))
+                transparentColor = line["TransparentColor = ".Length..];
+            else if (line == "Transparent = True")
+                transparent = true;
             else if (line.StartsWith("Picture.Data = {"))
                 hex = new StringBuilder(line["Picture.Data = {".Length..]);
         }
@@ -126,8 +135,27 @@ public static class Program
         Console.WriteLine("  wrote gfx/manifest.json");
     }
 
+    /// <summary>Delphi TColor: 0x00BBGGRR integer or a clXxx name.</summary>
+    static Color ParseDelphiColor(string value)
+    {
+        switch (value)
+        {
+            case "clBlack": return Color.FromArgb(0, 0, 0);
+            case "clWhite": return Color.FromArgb(255, 255, 255);
+            case "clRed": return Color.FromArgb(255, 0, 0);
+            case "clLime": return Color.FromArgb(0, 255, 0);
+            case "clBlue": return Color.FromArgb(0, 0, 255);
+            case "clNavy": return Color.FromArgb(0, 0, 128);
+            case "clFuchsia": return Color.FromArgb(255, 0, 255);
+            case "clYellow": return Color.FromArgb(255, 255, 0);
+            case "clAqua": return Color.FromArgb(0, 255, 255);
+        }
+        int v = int.Parse(value);
+        return Color.FromArgb(v & 0xFF, (v >> 8) & 0xFF, (v >> 16) & 0xFF);
+    }
+
     /// <summary>Delphi TPicture blob: [1B class-name length][class name][payload].</summary>
-    static void SaveGraphic(byte[] data, string outPath)
+    static void SaveGraphic(byte[] data, string outPath, Color? colorKey)
     {
         int nameLen = data[0];
         string cls = Encoding.ASCII.GetString(data, 1, nameLen);
@@ -135,14 +163,21 @@ public static class Program
 
         if (cls == "TPNGObject")
         {
-            File.WriteAllBytes(outPath, data[payloadStart..]);
+            // PNGs keep their native alpha (Omega honored it); key applies on top if set
+            byte[] png = data[payloadStart..];
+            if (colorKey != null)
+                SaveWithColorKey(png, outPath, colorKey.Value);
+            else
+                File.WriteAllBytes(outPath, png);
         }
         else if (cls == "TBitmap")
         {
-            // payload: [4B length][BMP bytes]
+            // payload: [4B length][BMP bytes]; key only when the item was marked Transparent
             int len = BitConverter.ToInt32(data, payloadStart);
-            var bmpBytes = new ReadOnlySpan<byte>(data, payloadStart + 4, len);
-            SaveBmpAsKeyedPng(bmpBytes.ToArray(), outPath);
+            var bmpBytes = new ReadOnlySpan<byte>(data, payloadStart + 4, len).ToArray();
+            using var ms = new MemoryStream(bmpBytes);
+            using var src = new Bitmap(ms);
+            SaveKeyed(src, outPath, colorKey);
         }
         else
         {
@@ -150,6 +185,27 @@ public static class Program
         }
     }
 
+    /// <summary>Re-encode as PNG with the given color made fully transparent (Omega's Transparent=True).</summary>
+    static void SaveWithColorKey(byte[] imageBytes, string outPath, Color key)
+    {
+        using var ms = new MemoryStream(imageBytes);
+        using var src = new Bitmap(ms);
+        SaveKeyed(src, outPath, key);
+    }
+
+    static void SaveKeyed(Bitmap src, string outPath, Color? key)
+    {
+        using var dst = new Bitmap(src.Width, src.Height, PixelFormat.Format32bppArgb);
+        for (int y = 0; y < src.Height; y++)
+            for (int x = 0; x < src.Width; x++)
+            {
+                var c = src.GetPixel(x, y);
+                bool keyed = key != null && c.A > 0 && c.R == key.Value.R && c.G == key.Value.G && c.B == key.Value.B;
+                dst.SetPixel(x, y, keyed ? Color.Transparent : c);
+            }
+        dst.Save(outPath, ImageFormat.Png);
+    }
+
     /// <summary>Convert BMP to PNG, keying out the bottom-left pixel color (Delphi Transparent convention).</summary>
     static void SaveBmpAsKeyedPng(byte[] bmpBytes, string outPath)
     {